City Of Reading
Wastewater Treatment Plant Projects
December 2014
 
Digester 4 & 5 Upgrade Project:
Digester #4 has been taken out of service and is being cleaned in preparation for inspection.  Both digesters 4 &5 will have their gas holder lids refurbished and structurally enhanced for the addition of linear motion mixers. New sludge pumps and heaters will also be added. Additional digestion capacity is required by the consent decree and will be needed when the major WWTP Upgrade Project takes place. 
             
 
To perform the structural upgrades and cleaning operations, the lid needed to be removed. This required the use of a massive 550 ton crane, which came with 8 flat bed tractor trailers of accessories, counter weights, and a very skilled team of workers. The actual lift took only approximately 12 minutes after many hours of crane set up and precise calculations and safety checks. After the lid is refurbished it will need to be lifted and very carefully placed back into digester #4. The lid from digester #5 will then be removed and refurbished / upgraded in the same manner. The digester lid measures 75 feet in diameter and weighs in at approximately 112,000 lbs. A time lapse video of the lift can be viewed below.
       

The structural upgrades are to allow for the installation and operation of a Linear Motion Mixer. Linear motion mixers are cutting edge wastewater technology that provides more thorough mixing of the sludge to promote more uniform sludge temperatures and better microorganism distribution throughout the tank. This improves digestion, gas production and solids reduction. They also cost significantly less to operate than conventional pumps.
 
Linear Motion Mixers are designed to mix various sludge types in all anaerobic digestion applications, in order to achieve a homogeneous mixture in tanks, while using up to 70% less power than with conventional mixers. The oscillating motion produces a flow pattern that approaches nearly isotropic (uniform) mixing without the turbulence intensity or vortices observed with rotary mixers.
 
Miscellaneous In House Wastewater Treatment Plant Improvement Projects: The wastewater plant is continually performing routine maintenance projects and other special projects to improve plant processes, efficiency and to make the working environment more safe for its employees. Below are a few projects recently completed by WWTP maintenance staff. 
  1. Potable Water valves were excavated and replaced due to age and signs of failure.
  2. Paving was completed at the 6th & Canal Pump Station after the recent force main upgrades were completed 
  3. The Grit Washer and piping at the Island Head works were refurbished and upgraded in house to provide greater flexibility in future maintenance operations and to repair some mechanical issues that had developed 
 

Wastewater Treatment Plant (WWTP) Design Project: The Wastewater Treatment Plant is working with RK&K Engineers on a $100 Million upgrade project. Upgrades to the aging plant and its technologies are needed to comply with the Department of Justice Consent Decree as per the capacities determined in the Act 537 Special Study (Wastewater Conveyance System Capacity Analysis).
 
Preliminary design discussions have recommended more efficient process operations throughout the facility.
 
On the wet side of the project,  the new design includes the addition of (4) four Activated Sludge Tanks, 3 (three) Final Settling Tanks, the conversion of the existing Tertiary Aeration Tank to (2) Chlorine Contact Channels and a new cascade effluent structure.
 
On the solids side of the project, the existing Solids Handling Building will be reconfigured to include 2 refurbished gravity belt thickeners and (2) sludge centrifuges. The end result will be a better quality, drier bio-solid saving costly dollars in landfill disposal hauling fees. 
 
The plant will also be redesigned to minimize the potential for flooding in extreme weather events. This involves relocation of specific processes to new locations at higher elevations and a new cascade outfall system designed to eliminate river backflow into the plant during high river flows.
 
The need for expansion and future Department of Environmental Protection requirements are also being considered in the design schematics. This would include the ability to add additional Activated Sludge Tanks and Clarifiers as needed due to future increased sewage flow from the city.
 
The future addition of Biological Nutrient Removal Tanks will be considered in the new design as well. Nutrient removal will likely become mandated by the Environmental Protection Agency and The Pennsylvania Department of Environmental Protection in the coming years to reduce phosphorous and other nutrients in our effluent.      
 
Environmental Operations Center Complex: A new “Operations & Maintenance Center” will be the epicenter for wastewater treatment plant functions. It will house our award winning Maintenance Department, Operations, our State Accredited Lab and administrative spaces for WWTP personnel. The O & M complex is as much needed to successful plant operations as is the new plant. Aging, structures some teams operating out of old trailers and general safety concerns make these new building a welcome addition to the new plant. The building will also have upgraded locker rooms / shower facilities, a conference room, a plan / records library, lunch rooms, and a vastly upgraded lab.